00:01
In your question, a random sample of 70 employees at a company shows that 62 of those are female.
00:08
We want to form a 95 % confidence interval for the proportion, it says proportion, of all employers who are female.
00:17
So the way we build a confidence interval is we have a statistic, plus or minus a margin of error.
00:32
Now your statistic in this case for your confidence interval should be your sample proportion.
00:37
Which would be 62 out of 70.
00:44
Then we'll have plus or minus.
00:46
Now, margin of error is made up of a critical value, which is given the symbol z star, times standard error.
00:56
Now, standard error, let me go ahead and just put the formula in there for that, is the square root of p hat times 1 minus p hat divided by your sample size.
01:09
Now, your question seems to only be interested in the margin of error.
01:13
This part right here.
01:15
But i do have to state that this sample proportion they have down is 0 .62.
01:21
I think that might be a mistake in your question because you should take 62 divided by 70 and that would come out to 0 .89 approximately instead of 0 .62...